Is there an old fitbit (least expensive) you can just plug into your computer.

[SunsetRunner]

I'm on a tight budget but I'd like to buy an old fitbit used on ebay. Do you know if there is one you can just plug into your computer without a dock? I only want it for walking (don't need any fancy features). I see tons listed for $20 called "fitbit charge 2" but the more I research the more I get confused about the differences. I only need it because I joined a group that gives perks for syncing your walking with their site (so you can prove it).  I just don't want to spend a bunch of money for something that simple. thanks!

[WendyB · Accepted solution]

You can compare them here

All of them will come with a charging device that hooks to your computer

[Williger]

Any of the Fitbit trackers will allow you to participate in challenges and track steps. In fact, you don't even need a Fitbit tracker to do this. I've got friends who joined Fitbit using their mobile phones as trackers, with a feature Fitbit offers called MobileSync. Fitbit trackers don't require a docking station (they sync through Bluetooth). You may be thinking of SportBrain, a predecessor to Fitbit which required either dial-up or USB docking station. SportBrain has been out of business for years and exists solely to patent troll tracker companies. 

Buy whichever tracker fits your budget and that you'll enjoy wearing, they'll all track your walking. Cheers!